"Hans Knappertsbusch was one of the most renowned and beloved conductors of the German Romantic repertoire in the middle twentieth century. He spent several summers as an assistant to director Siegfried Wagner and conductor Hans Richter at the Bayreuth Festival and took part in the Netherlands Wagner Festivals in 1913 and 1914. After the end of World War I Knappertsbusch worked in Dessau and Leipzig, and in 1922 he was asked to succeed Bruno Walter as music director of the Munich Opera.

Knappertsbusch's personality was easygoing; he was notably free of the restlessness and undue ambition that often attended a rising career such as his. He was content mainly to stay in Munich, with the result that he never became as well-known as many of his colleagues. In any case, Munich fully appreciated Knappertsbusch's talents, and he was named conductor for life. However, he refused several demands made by the Nazis and was fired from his lifetime post in 1936. He conducted a memorable SALOME in Covent Garden in 1936 and 1937, and made some guest appearances elsewhere in Germany, but was content to maintain a low profile during the Nazi regime. He left Germany after the Munich debacle, settling in Vienna where he frequently conducted the Philharmonic and the Vienna State Opera. Knappertsbusch's career was again affected by the Nazis when Germany took over Austria over in 1938, but he was mostly able to steer clear of trouble.

Knappertsbusch gained a reputation for broad, magisterial performances of Bruckner, and more and more seemed to emerge as the representative of the traditional style of unhurried Wagner performances. He was famous for disliking rehearsals, often cutting them short; his orchestral players maintained that this was not the result of laziness, but of complete security in his interpretation and trust of the players. His performances were therefore not rigidly preconceived, but instead had a remarkable freshness and spontaneity.

When the Bayreuth Festival reopened in 1951, Knappertsbusch worked closely with Wieland Wagner on orchestral matters (though the conductor was known to dislike the director's spare, revolutionary stage productions). Perhaps Knappertsbusch's most notable recording is his stereo account of Wagner's PARSIFAL from the Bayreuth stage."

- Joseph Stevenson, allmusic.com

“After an early career in provincial opera companies, Knappertsbusch succeeded Bruno Walter as conductor of the Munich Opera in 1922. Although he was fervently nationalistic and conservative, Hitler considered Knappertsbusch inept both as an opera manager and as an operatic conductor and in 1936 prohibited him from conducting anywhere in Germany. After several years as conductor at the Vienna Opera and the Salzburg Festival, he and Nazi-party authorities were reconciled. Hitler dismissed him as a ‘military bandleader’ but permitted him to conduct several times at the Nuremberg party rallies and at the celebration of his birthday. Knappertsbusch also conducted in occupied countries, once in Cracow at the invitation of the notorious Hans Frank, Governor of the rump state of Poland. After the war Knappertsbusch returned to Munich. He was known for his interpretations of Wagner and Bruckner and was a leading conductor at Bayreuth between 1951 and 1964, famed for his PARSIFAL performances.”

- Frederic Spotts, Great Conductors of the Third Reich

“The most important singer of the German Heldentenor repertory in the 1950s and 1960s, Wolfgang Windgassen employed his not-quite-heroic instrument, believable physique, and considerable musical intelligence to forge memorable performances on-stage and in the recording studio. Although his voice lacked the sensuous appeal of Melchior's or Völker's, it was never unattractive and never employed to obvious effect. Indeed, it conveyed a youthfulness that suited the young Siegfried especially well."

- Erik Eriksson, allmusic.com

“In the many performances I have appeared in, there were many wonderful colleagues who had me in raptures. There were those with magnificent voices, or great musicians, wonderful actors or great personalities. But George London had it ALL. He was as impressive on stage as he was the wonderful colleague and friend in his private life.”

“George London was a dramatic and very expressive singer. In many roles he sang like a demonic panther with a sound of purple-black in color. London was a singer favoring the drama in a piece, varying color to suggest shifts of mood. His acting on stage was described as overwhelming. The special magnetism of this artist is documented on his great recordings. Every role he sang was sung with utmost expression and unbelievable commitment, truly a singing-actor!”